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Photoshop Projects, Learning the Basics

Clark College

Instructor

Garry T. Stasiuk

Rule #1:
Never throw away data Always use a camera/scanners largest resolution --as measured in pixels, with the least amount or NO compression.

DPI

DPI (Dots per inch) has nothing to do with the resolution of a photograph. DPI only provides information to a printer as to how many dots to print per inch or tells the monitor how many dots per inch to display. Most monitors are set at 96 DPI

Camera Raw

Adobe's Camera Raw Plug-in supports unique raw file formats for 17 camera manufacturers and over 150+ different cameras. Adobe has their own raw file format called .DNG (Digital Negative)

White Balance and "Camera Raw"

When you shoot in "raw" format you have total control over white balance. In Adobe's Camera Raw or in any other image processor you can change the recorded White balance to any value from ...
2000 K



to 50,000 K

These settings are for final output to an inkjet printer.

R,G,B at 0,0,0 is the value for black ink.  By spreading out the black values we avoid pooling the black ink. (The darker the color the the greater the amount of ink the printer sprays on the paper)

R,G, B at 255. 255, 255 is white (no ink), lowering the white component reduces the possibility of have large areas of the canvas with no ink spay at all...

The setting (133) adds a little 'punch' to the mid-tones....

Here's another tidbit for you, and a real good reason to upgrade to the latest Photoshop software ---prior to CS3 and PSE 6 and Lightroom 1.3 The Contrast and Brightness controls were broken and never really worked as they were supposed to...!!! Hence the warnings about using contrast and brightness controls sparingly, if at all.

In Photoshop Elements there are no curve adjustments... so if I suggest using currves... In PSE use Levels instead!

Image File Formats

All files on a PC need to have a three letter extension that tells the computer the nature of the data,whether it is an executable program (.EXE), or a picture file, for example like:

pic-01.jpg

pic-02.tif

pic-03.raw

There are many other picture/image file formats, (digital cameras) save picture data in either .raw, .tif or .jpg formats.
The extensions can be written with upper or lower case letters.

Some Digital Cameras only save the picture data in .jpg format.

JPEG (.jpg)

Joint Photographic Experts Group - The name of the committee that designed the standard image compression algorithm.
JPEG (.jpg) is designed for compressing, either full-color or grey-scale digital images of "natural", real-world scenes, to save space on the computer and internet transmission time. It is a "lossy" type of storage because even in its highest quality mode the compression scheme throws away data.

Some cameras can also save using the .tiff (.tif) format.

TIFF (.tif)

- Tagged Image File Format -

An uncompressed image file format that is lossless and produces no artifacts as is common with other image formats such as JPG
Most higher end cameras (SLR's) can save picture data using a file format called "RAW" Almost all camera manufacturers have their own proprietory "raw" format.

RAW (.raw)

- RAW files contain the raw unprocessed data imaged by the camera or scanners sensor usually at 12 - 14 bits per channel Usually using a lossless compression routine is applied to the data to reduce file size without compromising quality.

Which one do you use? It's Dictated by intended use!

1. RAW if you are a serious photographer or it's a "money" shot, or you are trying to capture a scene where there is a large dynamic range The raw data includes data spanning at least 2 f/stops and your choice of white balance, and more...
For more info about RAW Format, read The following Article: The RAW Truth, by Michael Tapes

2. .TIF if you need to preserve detail.

3. .JPG

If you are shooting for the internet, you only intend to make small prints up to 8 x 10 or you are going to hand the photo off to a client WITHOUT PREPROCESSING. Always(Use high, super fine, quality....) Caveat. Every time a picture is saved in .jpg format, data is lost, in other words the compression artifacts get worse every time the picture is saved in Jpeg format...

Sample of JPG Compression Artifacts

Comparison of Compressed jpg and uncompressed Tif File

Note the JPG banding in the clouds

Exposure! It's all about exposure.

Rule #1: Never Throw Away Data

How do you know that the color you see on the screen is what the camera captured and why doesn't my printed colors match what I see on my computer screen???

Rule #2 Calibrate everything!

A Brief Introduction to PhotoShop Image Processing

First steps

Before we can actually do image processing we need do the following:

In PhotoShop or PhotoShop Elements

1. Set Color Management.

Setting the color space

	1. ProPhoto RGB        (Largest Color Gamut)             	      
	2. Adobe RGB                
	3. sRGB                (Color gamut matches CRT monitors)		
		

Choose the largest color gamut available. In Photoshop the menu item is File > File Info... Image Data, the EXIF Meta data for an image is available in the Adobe Browser -- or Bridge using the Meta data Tab.

Set the following In Photoshop look for the menu item "Edit/Color Settings..." on the Mac the menu is "PhotoShop/Color Settings"

Click on the button that says "Full Color Management"...

 In Photoshop or other programs choose Adobe RGB
the rest  we explain in class...

2 Setting  the eye dropper sampler

Choose sample size  3 by 3 Average

The eye dropper is found in the tool bar. Select it by clicking on it.
Then look for the options tool bar. If it is not visible the menu item is
Windows > Options

In the options bar click the check mark and choose 3 x 3 Average 3.

3. Setting Black, Mid-gray and White values for layers and curves

In Photoshop Elements 

Look Under the Enhance menu select Adjust Lighting > Levels
In Photoshop CS, CS2, etc
The menu is
Layer > New Adjustment Layer > Levels...
Keyboard shortcut:
on th PC is Control L,
 Mac it's Command L.

To set the black point double click the Black eye dropper

• Change
• R setting to 10
• G setting to 10
• B setting to 10

then click okay To set the White Point

double click the White Eye Dropper

• Change
• R setting to 240
• G setting to 240
• B setting to 240

then click okay To set the Gray Point double click the Grey Eye Dropper

• Change
• R setting to 133
• G setting to 133
• B setting to 133

then click okay

Now click okay in the requester will pop up that asks if you want to "save the new target colors as defaults?"

Click Yes

Now were ready to Image Process.

Rule #4: Do not assume..that if the picture you are photographing doesn't turn out, you can fix it in Photoshop,  ImageFX  or some other image processing software. You will be sorely disappointed! Remember, with a digital camera, you don't use film... you can shoot until you run out of storage memory and you can always delete (heaven forbid)  failed pictures.

Always remember this Absolute Rule:  Do Not, not ever,  Throw Away Data!

• Use contrast and brightness controls carefully and sparingly as these tools changes whole pixel values... you actually wind up throwing away information when you save the result. In other words, the data you changed using contrast and brightness is a one way street...there is no way to get back to the original data set.
• Use and exaggerate color balance controls: R, G, B, or Hue / Saturation, or CYMK
• These functions control or manipulate data in the colour look up table, only changing their values not not throwing them away. You can reset or revert the "color look up data" back to its original state, even after you have saved the changes.
• Do Not Throw Away Data
• Never change image resolution.
• Yep, you got it, Do Not Throw Away Data.

Level Controls
You can use "Levels" to adjust color tone The test picture was shot in Guadalajara, Mexico on a dark sunless street, right around sunset, using a Nikkormat FT2 with a Vivitar f/2.8 28 90mm lens on KodaChrome 64 slide film.

Ugh, it's way dark...The fix is to work with the mid grays. this is done using the "Levels" function and the sliders under the histogram's bell curve.

Here's what the controls do in The "Levels" Dialogue box

Don't forget to flatten and save the "enhanced" picture.

For an excellent getting up to speed tutorial on using PhotoShop go here... http://luminous-landscape.com/tutorials/instant_photoshop.shtml

Here's the details about the curves Dialogue box...

Layers

How it works...


http://www.photoshopcafe.com/tutorials/layers/Layers.htm



A tutorial for fixing Under and over exposed photos


Over Exposed Instructions